In a new radio access technology (NR) system, DeModulation Reference Signal (DMRS) supports up to 12 orthogonal ports, and DMRS port multiplexing methods include: Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Time Domain-Orthogonal Cover Code (TD-OCC) multiplexing, Frequency Domain-Orthogonal Cover Code (FD-OCC) multiplexing and Frequency Domain-Cyclic Shift (FD-CS) code multiplexing.
In an actual deployment, there is phase noise in radio frequency modules of a 5G base station (gNB) and a user equipment (UE), so that a common phase Error (CPE) exists in each Orthogonal Frequency Division Multiplexing (OFDM) symbol. The NR system introduces a Phase Tracking Reference Signal (PT-RS) for estimating the CPE so as to improve a success rate of demodulating data.
In existing product programs, there is no solution for a subcarrier location where a PT-RS associated with a DMRS port is located, resulting in failure in product achievement.